If your estimated delivery date is changing there might be a problem with your address. They are cross-checking for your address and that is why the order has not been shipped yet. After confirming your address you will receive your order soon. Maybe your item has gone out of stock just while you are ordering. In that case, your order shipment will be late. Immediately after restocking your order, your order will be shipped and you will receive your package. If you have purchased an item from a third-party seller, it takes time. The process for the order and shipment will take time if it has been ordered from a third-party seller. As soon as the seller ships the package it will reflect on your app.
